"the same as" and "as same as"

What is the difference between both? Why is “as same as” not accepted

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It is logically redundant, and not a part of English grammar. As…as = the same…

My hair is as grey as my beard.
My hair and my beard are the same grey.

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Hi,
As i know , 'as long as ’ is similar to ‘if’,
If i want to compare the length with two objects, can i say 'A is as long as B" ?

Hi Felix,

You can say ‘this street is exactly as long as Burbon Street in London’.

And, as long as I can remember, there have been red lanterns there.

As long as you do your homework, you’ll be invited to dinner.